Anti-Buckling Latch for a Fiber Optic Connector

ABSTRACT

A fiber optic connector includes a housing and push-pull boot with a latch body disposed between a front extension of the push-pull boot and a top side of the housing. The latch body has an anti-buckle feature, which may be a projection. The anti-buckle feature movable between a relaxed position and a stressed position, wherein the anti-buckle feature is in contact with the housing in the stressed position to prevent the latch body from buckling.

REFERENCE TO RELATED CASE

This application claims priority under 35 U.S.C. § 119 (e) to U.S.provisional application No. 63/091,451 filed on Oct. 14, 2020, and under35 U.S.C. § 120 to U.S. patent application Ser. No. 17/501,729, filed onOct. 14, 2021, the contents of both of which are hereby incorporated byreference in their entirety.

Certain fiber optic connectors have push-pull features that allow forcoupling to adapters. One such exemplary connector is the Mini DuplexConnector (MDC) that has a push-pull boot and is disclosed inApplicant's International Patent Application Pub. No. WO 2019/195652entitled “Flexible Push-Pull Boot and Crimp Body for Fiber OpticConnector,” filed Apr. 5, 2019 (“the '652 publication”). See alsoInternational Patent Application Pub. No. WO 2019/126337.

One observation in the design of such fiber optic connectors is that alatch body attached to a front extension of the boot may buckle duringpulling under certain circumstances. For example, the latch body maybuckle when angular or even perpendicular downward forces are applied tothe fiber optic cable attached to the fiber optic connector. Theseforces may be intentionally applied, for example, during proof-loadtesting per Telcordia standards, or may be accidentally applied due tosnagging of the optical fiber cable. As a result of this undesiredbuckling, the connector may erroneously delatch from the adapter or thereceptacle in which the connector resides for mating.

Accordingly, what is needed is an improvement in the latch body thataddresses the above-noted observation and rigorously meets therequirements for standard testing procedures.

SUMMARY OF THE INVENTION

According to one aspect, the present invention is directed to afiber-optic connector that includes a housing having an openingextending between a front end and a rear end with an optical fibersupport structure disposed within at least a portion of the opening, theoptical fiber support structure to support at least two optical fibersdisposed therein, a crimp body attached to the rear end of the housing,a push-pull boot attached to the crimp body, a front extension attachedto the push-pull boot, to the crimp body and the housing, and a latchbody disposed between the front extension and a top side of the housing,the latch body having an anti-buckle feature disposed thereon andextending beyond a bottom surface thereof, the anti-buckle featuremovable between a relaxed position and a stressed position, wherein theanti-buckle feature is in contact with the housing in the stressedposition of the latch body.

In some embodiments, in the stressed position, the anti-buckle featureis in contact with a top side of the housing, and in the relaxedposition, the anti-buckle feature is separated from the housing.

In some embodiments, the anti-buckle feature is positioned at an angledmiddle portion of the latch body.

In some embodiments, the anti-buckle feature is positioned at an angledmiddle portion of the latch body longitudinally between a projection anda flange of the latch body.

In some embodiments, the anti-buckle feature is a projection.

In yet another aspect, there is a fiber-optic connector that includes ahousing assembly having an opening extending between a front end and arear end with an optical fiber support structure disposed within atleast a portion of the opening, the optical fiber support structure tosupport at least two optical fibers disposed in the fiber-opticconnector, a push-pull boot attached to the housing assembly, a frontextension attached to the push-pull boot and to the housing assembly,and a latch body disposed between the front extension and a top side ofthe housing, the latch body having a front portion engaged to the frontextension; and an anti-buckle feature disposed between the latch bodyand the housing assembly, wherein the anti-buckle feature is configuredto block the latch body rearward of the front portion from contactingthe housing assembly when the fiber-optic connector is pulled.

In some embodiments, the anti-buckle feature is configured to block thelatch body rearward of the front portion from contacting the housingwhen the latch body is in a stressed position.

In some embodiments, the anti-buckle feature is attached to a bottomsurface of the latch body rearward of the front portion.

In some embodiments, the anti-buckle feature is attached to the top sideof the housing rearward of the front portion of the latch body.

In yet another aspect, there is a latch body for use with a fiber opticconnector having a housing with a top housing surface and a bottomhousing surface that includes a main body having a front portion, amiddle portion and a rear portion, a latch extending outward from themiddle portion, a rail portion extending along side portions of the mainbody at least partially along the front portion to slidably engage thefiber optic connector housing on one of the top housing surface and abottom housing surface, an anti-buckle feature extending beyond a bottomsurface of the main body toward the housing is provided, the anti-bucklefeature movable with the latch body between a relaxed position and astressed position, wherein the anti-buckle feature is in contact withone of the top housing surface and a bottom housing surface in thestressed position of the latch body.

It is to be understood that both the foregoing general description andthe following detailed description of the present embodiments of theinvention are intended to provide an overview or framework forunderstanding the nature and character of the invention as it isclaimed. The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated into and constitutea part of this specification. The drawings illustrate variousembodiments of the invention and, together with the description, serveto explain the principles and operations of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of a fiber opticconnector according to the present invention;

FIG. 2 is a partial exploded perspective view of the fiber opticconnector in FIG. 1 ;

FIG. 3 is a top perspective view the fiber optic connector in FIG. 1showing the latch body attached to the housing thereof;

FIG. 4 is a cross section view of the fiber optic connector in FIG. 1 ;

FIG. 5 is a top perspective view from the upper right of the latch bodyfor the fiber optic connector in FIG. 1 ;

FIG. 6 is a bottom perspective view of the latch body in FIG. 5 from thelower right;

FIG. 7A is a top planar view of the latch body;

FIG. 7B is a bottom planar view of the latch body;

FIG. 7C is an elevational view of the left side of the latch body;

FIG. 8A is a perspective view of the latch body from the bottom showingthe latch body and the front extension of the fiber optic connector;

FIG. 8B is a cross section view of the latch body and front extensionalong the line 8B-8B from FIG. 8A;

FIG. 9 is an elevational view of a cross section view of the fiber opticconnector in FIG. 1 showing the forces on the latch body;

FIG. 10A is a side elevational view of a prior art latch body in arelaxed position;

FIG. 10B is a side elevational view of a prior art latch body without ananti-buckle feature in a stressed position;

FIG. 11 is a perspective view of another embodiment of a housing to usewith a fiber optic connector according to the present invention with theanti-buckling feature on the housing or a housing assembly; and

FIG. 12 is a cross sectional view of another embodiment of a housing touse with a fiber optic connector according to the present invention withthe anti-buckling feature attached to the front extension.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the present preferredembodiment(s) of the invention, examples of which are illustrated in theaccompanying drawings. Whenever possible, the same reference numeralswill be used throughout the drawings to refer to the same or like parts.

Illustrated in FIGS. 1-4 is one embodiment of a fiber optic connector100 according to the present invention. The fiber optic connector 100preferably includes a housing assembly 102, an integrated push-pullpolarity boot 104, and optical fiber support structures 106. The housingassembly 102 preferably has a housing 108 and a crimp body 110 that areremovable from one another. As an alternative embodiment, the housingassembly 102 may also be a single unit where the housing portion 108 andthe crimp body portion 110 are integral, either through adhesion(gluing, welding, etc.) or because they were molded at the same time.The optical fibers (not shown) are inserted from the rear of the fiberoptic connector and may be in a cable or other protective structure 112.There may also be other elements that are included with the fiber opticconnector 100, such as springs to bias the optical fiber supportstructures 106, a crimp band, lead-in tubes, etc. It is also possiblethat the illustrated structures take other forms and configurations. Oneexample would be the optical fiber support structures 106. The opticalfiber support structures 106 are illustrated as two single fiber opticferrules that are at least partially surrounded by the housing assembly102 and have the optical fibers secured therein. However, the fiberoptic connector 100 may also have more optical fibers that are supportedusing other types of optical support structures 106. For example, theycould be replaced using a miniature MT ferrule, such as the onedescribed in Applicant's Patent Application no. PCT/US21/28919, entitled“Miniature Multi-fiber Ferrule,” filed Apr. 23, 2021. The opticalsupport structures 106 may have a flat end face or an angled end facefor physical contact with another mating optical support structure.Alternatively, there may be lenses at the ends of the optical supportstructures 106 that still mate the fiber optic connector 100 withanother fiber optic connector without any physical contact. For example,a lensed clear ferrule may be provided to support the optical fibers.

The integrated push-pull polarity boot 104, as illustrated, has a rearportion 104 a that provides a grasping structure, as well as strainrelieves the optical fibers. The integrated push-pull polarity boot 104also has a main body 104 b that is attached to the rear portion 104 aand also to the crimp body 110 (or in the alternative embodiment, to thehousing assembly 102). However, the main body 104 b of the integratedpush-pull polarity boot 104 may also be attached to the housing 108 andnot directly to the crimp body 110.

Extending in a forward direction from the main body 104 b and over thehousing assembly 102 is front extension 104 c. The front extension 104 calso provides a keying function or identifies the polarity of the fiberoptic connector 100. As will be recognized by one of skill in the art,the presence of the front extension 104 c of the integrated push-pullpolarity boot 104 prevents the fiber optic connector 100 from beinginserted into an adapter or other connection device (not shown) in thewrong polarity (receive to receive, for example).

Applicant notes that the term “front” or “forward” means that directionwhere the fiber optic connector 100 would meet with another fiber opticconnector or device, while the term “rear” or “rearward” is used to meanthe direction from which the optical fibers enter into the fiber-opticferrule or the fiber optic connector 100. In the present application,the fiber optic connector 100 will therefore have a front and a rear,the front will be inserted into an adapter or other receptacle. Thus, inFIG. 1 , the “front” of the fiber optic connector 100 is on the leftside of the figure and pointing out of the figure. The “rear” or “back”is that part of the fiber optic connector 100 is on the right side ofthe page and “rearward” and “backward” is toward the right and into thepage.

The housing assembly 102 (and indeed the fiber optic connector 100 andits other components) may also have what is labeled a top side 102 a anda bottom side 102 b, but those labels are to assist in the explanationof the invention and are a convention only. It should also be noted thatthe top side 102 a bottom side 102 b are generally the shorter sides 102c of the fiber optic connector 100 and the housing assembly 102. Thatis, the housing 108 may be flipped so that the labeled top side 102 a ison the opposite side of the front extension 104 c of the integratedpush-pull polarity boot 104.

The housing assembly 102 has an opening 114 extending between a frontend 116 and a rear end 118 with the optical fiber support structure 106disposed within at least a portion of the opening 114. See, e.g., FIGS.4 and 9 . The optical fiber support structures 106 should support atleast two optical fibers disposed in the fiber-optic connector 100. Thecrimp body 110 would also have an opening 122 that is in communicationwith the opening 114 to allow for the optical fibers to passtherethrough. See FIG. 4 . The crimp body 110 extends between a frontend 124 and a rear end 126 thereof.

The fiber optic connector 100 also includes a latch body 130 that isdisposed between the housing assembly 102 and the front extension 104 cof the integrated push-pull polarity boot 104. The latch body 130 has anangled latch 132 that engages the adapter or other receptacle into whichthe fiber optic connector 100 is inserted. The fiber optic connector 100can be inserted into and removed from the adapter or other receptacle byusing the integrated push-pull polarity boot 104. The integratedpush-pull polarity boot 104 controls the positioning of the angled latch132 as will be explained below.

Turning to FIGS. 5-9 , the latch body 130 has an elongated main body 134that has a generally flat or level front portion 136, a middle portion138 that is angled upward from the front portion 136 to the angled latch132, and a generally flat rear portion 140, although there may be somedownward angling thereof. The latch body 130 has a top surface 142 and abottom surface 144. The front portion 136 has a cross bar 146 that isperpendicular to a line A connecting the front portion 136, the middleportion 138, and the rear portion 140. See FIG. 7A. Somewhat rearward ofthe crossbar 146, but still within the front portion 136 and extendingfrom the bottom surface 144 is an engagement portion 148 that engages aportion of the front extension 104 c of the integrated push-pullpolarity boot 104. As illustrated best in FIGS. 2, 3, and 8B, the mainbody 134 is positioned within a slot 150 in a front portion of the frontextension 104 c and the engagement portion 148 includes two lobes 148 aand 148 b to engage a portion of the front extension 104 c adjacent tworails 152 on either side of the front extension 104 c. See FIG. 8A. Thetwo rails 152 of the front extension 104 c in turn engage an opening 160on the top side 102 a of the housing 108 (see, FIG. 3 ). The opening 160in turn includes receptacles 162 on either side of the opening 160 toreceive the rails 152 to connect the front extension 104 c to thehousing 108. See FIGS. 2, 8A, 8B, and 9 .

It should be noted that the main body 134 could have a slot therein onthe bottom surface 144 so that the lobes 148 a and 148 b could beseparated more from each other. The cross bar 146 is not disposed withinthe opening 160, but extends forward of the opening 160 towards thefront end 116. See FIGS. 3 and 4 .

Turning back to FIG. 2 , the front extension 104 c has a window 164 toallow the angle latch 132 to extend upward out of the fiber opticconnector 100 to engage the adapter or the receptacle into which thefiber optic connector 100 is inserted. The front extension 104 c alsohas a space 166 to receive the rear portion 140 of the latch body 130.The rear portion may have a flexure member 168, which acts as a type ofspring mechanism when the integrated push-pull polarity boot 104 iseither pulled or pushed. The flexure member 168 biases the frontextension 104 c (and hence, the push-pull polarity boot 104) in aforward direction.

The latch body 130 also has an anti-buckle feature 170 that preferablyextends from the latch body 130 below the bottom surface 144. Theillustrated anti-buckle feature 170 has an arcuate shape (part of acircle) that extends from the bottom surface 144. However, theanti-buckle feature 170 could have other forms (e.g., pyramidal profileor a trapezoidal profile) and could extend from the sides of the mainbody 134. While only one anti-buckle feature 170 is illustrated, therecould be two or more that are separated from each other across the mainbody 134. As noted above, one could extend from each of the sides of themain body 134 or be separated across the bottom surface 144. Theanti-buckle feature 170 (in both embodiments) is disposed between thelatch body 130 and the housing 108 (or the housing assembly 102). In afront to back direction, the anti-buckling feature 170 is the disposedwithin the middle portion 138 of the latch body 134 between theengagement portion 148 and flanges 154. The anti-buckle feature 170 isconfigured to block the latch body 134 rearward of the front portion 136from contacting the housing assembly 102 when the fiber-optic connector100 is pulled. For example, the anti-buckle feature 170 may be providedon an underside of the middle portion 138. However, in alternativeembodiments, the anti-buckle feature 170 may be provided on othercomponents of the fiber optic connector 100 (e.g., on the housingassembly 102 or the front extension 104 c, as described below herein),as long as the latch body 134 is prevented from buckling under stress.

Turning to FIGS. 10A and 10B, the reason for the anti-buckle feature 170will be described. In FIG. 10 , a conventional latch body 230 withoutthe anti-buckle feature 170 is illustrated and it is in a relaxedcondition. That is, there are no forces operating on it. The latchingsurface 232 makes an angle α1 with a vertical axis. In FIG. 10B, thereare forces being applied to the latch body 232, and the middle portion234 of the latch body 230 is deformed by bending in the middle portion234. The latching surface 232 now makes an angle α2 with the verticaland α2 is much greater than α1. That is, the latch body 230 bucklesunder stress, as indicated by the bent shape in FIG. 10B. This change inthe angle of the latching surface 234 causes the fiber optic connector100 to fall out of or to be more prone to accidental removal from theadapter or receptacle. Such accidental delatching of the fiber opticconnector 100 may cause increase in optical losses, or even failure ofthe optical connection that the fiber optic connector 100 implements.

Referring to FIG. 4 , the fiber optic connector 100 and the latch body130 are in a first, relaxed position. The anti-buckle feature 170 is notengaging the top side 102 a (or, is not in contact) of the housing 108.That is, there is a gap or space between the anti-buckle feature 170 andthe top surface 102 a of the housing 108. As shown in other embodimentsof FIGS. 11, 12 , the anti-buckle feature 170 may be provided elsewhereas long as the middle portion 138 of the latch body 130, or elsewherebehind the front portion 136 of the latch body 130. In FIG. 9 , whenthere is a force applied to the latch body 130, the middle portion 138may bend slightly, until the anti-buckle feature 170 engages the topside 102 a of the housing 108. This position is a second, stressedposition. The anti-buckle feature 170 prevents the latch body 130 frombuckling as illustrated in FIG. 10B. If the latch body 130 does not bendin this stressed position, then the latch surface (e.g., of the middleportion 138) will not buckle, distort in shape, or bend, or rotate, andsubsequently disengage the latch body 130 from the adapter or otherreceptacle.

As illustrated in FIG. 11 , the anti-buckle feature 170′ could be on thehousing 108′ instead. And as illustrated in FIG. 12 , the anti-bucklefeature 170″ for fiber optic connector 100″ need not be attached to thehousing 108″ or the latch body 130″. Rather it can be attached to thefront extension 104 c″ by way of a support structure 104 d″ that extendsthe anti-buckle feature 170″ to a position between the latch body 130″and the housing 108″. While the anti-buckle feature 170″ is illustratedas a block, it could take any appropriate form. Additionally theanti-buckle feature 170″ could also be attached to the front extension104 c″ in any appropriate way or location.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the present inventionwithout departing from the spirit and scope of the invention. Thus it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

We claim:
 1. A fiber-optic connector comprising: a housing having anopening extending between a front end and a rear end with an opticalfiber support structure disposed within at least a portion of theopening, the optical fiber support structure to support at least twooptical fibers disposed therein, wherein the housing has a top side anda bottom side joined together by two opposing side walls; a push-pullboot attached to the housing; a front extension attached to thepush-pull boot and the housing; and a latch body disposed between thefront extension and the top side of the housing, the latch body having afront end and a latch on a middle portion rearward of the front portion,the latch engageable with an adapter or a receptacle, wherein the latchbody includes a projection disposed underneath a bottom surface thereofand between the front end and the latch, and wherein the projection isconfigured to maintain a separation between the latch body and thehousing in a stressed position of the latch body.
 2. The fiber-opticconnector of claim 1, wherein the latch body comprises a flexure memberat a rear end thereof.
 3. The fiber-optic connector of claim 1, whereinin the stressed position, the projection is in contact with the top sideof the housing, and in a relaxed position of the latch body, theprojection is separated from the housing.
 4. The fiber-optic connectorof claim 1, wherein the projection is positioned at an angled middleportion of the latch body.
 5. The fiber-optic connector of claim 1,wherein the projection is positioned at an angled middle portion of thelatch body longitudinally between an engagement portion and a flange ofthe latch body.
 6. The fiber-optic connector of claim 5, wherein theengagement portion includes at least one lobe to engage the frontextension.
 7. The fiber-optic connector of claim 1, further comprising acrimp body attached to the rear end of the housing and to the push-pullboot.
 8. The fiber optic connector of claim 1, wherein the projection isintegral to the latch body.
 9. A fiber-optic connector comprising: ahousing assembly having an opening extending between a front end and arear end with an optical fiber support structure disposed within atleast a portion of the opening, the optical fiber support structure tosupport at least two optical fibers disposed in the fiber-opticconnector; a push-pull boot attached to the housing assembly; a frontextension attached to the push-pull boot and to the housing assembly,and extending toward the front end away from the push-pull boot; and alatch body disposed between the front extension and a top side of thehousing assembly, the latch body having a front portion engaged to thefront extension and a middle portion rearward of the front portion,wherein the middle portion includes an angled latch to engage an adapteror a receptacle configured to receive the fiber-optic connector; and aprojection disposed underneath the latch body and between the frontportion and the angled latch.
 10. The fiber-optic connector of claim 9,wherein the projection is configured to block the latch body rearward ofthe front portion from contacting the housing assembly when the latchbody is in a stressed position.
 11. The fiber-optic connector of claim9, wherein the projection is attached to a bottom surface of the latchbody rearward of the front portion.
 12. The fiber-optic connector ofclaim 11, wherein the projection does not contact the housing assemblywhen the latch body is in a relaxed state.
 13. The fiber-optic connectorof claim 9, wherein the projection is attached to the top side of thehousing assembly rearward of the front portion of the latch body.
 14. Alatch body for use with a fiber optic connector having a housing with atop housing surface and a bottom housing surface comprising: a main bodyhaving a front portion, a middle portion and a rear portion; a latchextending from the middle portion away from the main body; an engagementmechanism to engage the main body with a fiber optic connectorsupporting at least two optical fibers; and a projection disposedunderneath a bottom surface of the main body between the housing of thefiber optic connector and the main body, the latch body bendable betweena relaxed position and a stressed position upon an application of aforce, wherein the projection is configured to maintain a separationbetween the main body and one of the top housing surface and the bottomhousing surface in a stressed position of the latch body.
 15. The latchbody according to claim 14, wherein the rear portion is a flexuremember.
 16. The latch body according to claim 14, wherein in thestressed position, the projection is in contact with a top side of thehousing, and in the relaxed position, the projection is separated fromthe housing.
 17. The latch body according to claim 14, wherein theprojection is positioned at the middle portion of the latch body, themiddle portion being angled relative to the front portion.
 18. The latchbody according to claim 14, wherein the projection is positioned at themiddle portion of the latch body longitudinally between the engagementmechanism and a flange of the latch body.
 19. The latch body accordingto claim 14, wherein the engagement mechanism is a rail portionextending alongside portions of the main body at least partially alongthe front portion.
 20. The latch body according to claim 14, wherein theprojection is positioned between the front portion and the latch on themiddle portion of the latch body in a longitudinal direction.